Collecting Production Line Data with the Data Output Node

Created on 2012-02-10 19:21:00

The new Data Output node provides a simple way to save measurement data from an automated APx project running on a production line to a CSV file. To make use of it, check the box beside Data Output at the bottom of the APx500 navigator. If you wish, you can right-click on it to change the default file name.

APx500 navigator, Data Output node at bottom.

Fig 1  Data Output node in APx500.

Each time an automated sequence is run, all single-point measurement results will be appended to a new line in the file. Single point measurements include Level and Gain, THD+N, IMD, Signal to Noise Ratio, Maximum Output, Crosstalk, Phase, Bandpass, DC Level, Frequency, and Noise. If the file does not already exist at run time, a new one with column headers will be created. If you change the selected measurements or the number of channels in a project sequence after being run the first time, be sure to delete the file so that a new one with the correct headers is created.

Chart with columns for date, time, device ID, result, THD+N ratio, and THD ratio.

Fig 2  CSV file output (raw data formatted in Excel for clarity).

The “Prompt User for Device ID” option in Project/Sequence Properties goes hand-in-hand with this feature. When checked, the user is prompted to enter a device ID, such as a serial number, each time the sequence is run (using the keyboard, or alternatively with a barcode scanner). The ID flows into reports and into a column in the Data Output file.

Prompt user for device ID checkbox on start tab.

Fig 3  Project/Sequence Properties.

The CSV output file is not only useful for record keeping, but for quality control analysis. Below is a trendline chart made in Microsoft Excel using the data shown in Figure 2 above.

XY graph, THD+N and THD points and trendline for device IDs 101-105.

Fig 4  Trendline chart from CSV file data.